Top Strap:
CO 200 sts
knit 3 rows in garter stitch (knitting each row)
At the beginning of the next 2 rows, cast off 75 stitches.
K 1 more row.
Mask:
Row 1: K
Row 2: K5, P to last five stitches, K5
Repeat rows 1&2 once more.
Short Row Shaping: Use your preferred short row method (wrap and turn or yarnover would be best) to work a total of 6 rows in shaping. I spaced them one right next to each other to mimic the folds in a real surgical mask. Here is the shaping method I used.
Row 1: K to last 5 stitches, turn work.
Row 2: YO, P to last last 5 stitches, turn work.
Row 3: YO, K to last 6 stitches (not counting YO), turn work.
Row 4: YO, P to last 6 stitches (not counting YO), turn work.
Row 5: YO, K to last 7 stitches (not counting YO), turn work.
Row 6: YO, P to last 7 stitches (not counting YO), turn work.
Row 7: K to end of the row (SSK the yarnovers and adjacent knits as you come to them).
Row 8: P to end of the row.(P2tog yarnovers and adjacent purls as you come to them)
To Finish the mask, knit as follows:
Knit rows 1&2 of "Mask" 4x
Repeat Short-row shaping.
Knit rows 1&2 of "Mask" 4x
Repeat short row shaping
Knit rows 1&2 of "mask" 2x
At the end of the last row, cast on (either backwards loop, cable, or knitted-on cast-on are appropriate) 12 stitches.
Knit across the next row, then cast on 12 stitches at the end of the row.
Knit 2 rows plain, then cast off knitwise.
Stitch the ends of the the shorter ties so that the form a comfortable triangle with the longer ties.
Nose:
Cast on 40 stitches and divide between DPNs with 13 stitches on the 1st and 2nd needles, and 14 stitches on a 3rd.
K 8 rows
P 1 row
SSK the first two stitches on the needle, K to last 2 stitches, k2tog. Repeat until you can no longer decrease in this manner. Cut the yarn, thread through remaining stitches 2x and then pull it tight, weave the end in on the other side.
At this point, i whip-stitched the black nostrils on the mask. you don't have to, you don't have to use black... Whatevs! it's all good! You'll notice the nostril is slightly triangular, but the base stays kind of circular.
When i made the mask, i intended the cast on edge to be the top, but i carelessly stitched the whole nose down to the wrong side. don't make this mistake - it works better if your cast on edge is the top. Stitch the nose down to the middle, still keeping it approximately circular. It works really well if you just whip stitch it. If it's in the same yarn as you knit the whole thing, it doesn't really matter cus you won't really see it. Voila! Swine Flu mask! (don't forget to weave in your ends)